POS1565 ACUTE PERICARDITIS WITH PLEUROPULMONARY INVOLVEMENT, FEVER AND ELEVATED C-REACTIVE PROTEIN: A SYSTEMIC AUTOINFLAMMATORY DISEASE? A COHORT STUDY
Authors: A. M. Pisacreta, R. Mascolo, M. Nivuori, C. Caccia, G. DI Marco, C. Carollo, A. Pedroli, F. Casarin, E. Tombetti, A. Brucato
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Pericardial diseases may involve only the pericardium, or may be part of a systemic condition, with an inflammatory phenotype sharing similarities with autoinflammatory diseases. <h3>Objectives</h3> This cohort study aims to describe the prevalence and features of systemic phenotype of pericarditis characterized by pleuropulmonary involvement, fever, and elevation of C-reactive protein (CRP), comparing this phenotype with other forms of pericarditis. <h3>Methods</h3> All patients in our center were enrolled in a prospectively maintained registry from 2019 to 2022. 412 patients with idiopathic recurrent pericarditis were analyzed. "Systemic" subset was defined as the presence of all of the following criteria: fever &gt; 38 C°, CRP higher than 2 times normal values, pleural effusion detected with any imaging techniques. The absence of any of the 3 criteria was defined as "isolated" subset. <h3>Results</h3> We found that 211 (51.2%) of 412 patients presented the systemic subset and the variables significantly associated with this subset in univariate analysis (p&lt;0.001) were: higher mean age of onset 45.5 (±SD 17.2) vs 39.9 (±SD 16.4) years, higher mean CRP values 128.8 (95% CI 117.8-139.8) vs 49.9 (95% CI 41.5-58.3) mg/L, higher proportion of pericardiocentesis 40 (19%) vs 3 (1.5%), higher mean leukocyte count 13143.3 (95% CI 12790.4-13496.2) vs 9910.3 (95% CI 9556.2-10264.4)/mm<sup>3</sup>, higher mean neutrophils number 10402.5 (95% CI 10082.1-10723) vs 6779.8 (95% CI 6505.2-7054.4)/mm<sup>3</sup> and lower mean lymphocyte count 1693.9 (95% CI 1621.9-1765.8) vs 2079.3 (95% CI 1979-2179.6)/mm<sup>3</sup>. As results the neutrophil-to-lymphocyte ratio was higher in systemic phenotype: 6.6 (95% CI 6.2-6.9) vs 3.4 (95% CI 3.3-3.6). Anti-IL1 therapy was started more frequently in the systemic subgroup (55/211, 26%) than in the isolated subset (15/201, 7.5%) (p &lt; 0.001). On multivariate analysis neutrophil count and lymphopenia, were statistically associated with the systemic subset (p &lt; 0.001). <h3>Conclusion</h3> These results demonstrate the clinical relevance of the systemic phenotype in a referral center and confirm its analogy with the autoinflammatory diseases, suggesting a pivotal role of IL1 in the genesis of this subset. <h3>References</h3> [1]Lopalco G, Rigante D, Cantarini L, et al., The autoinflammatory side of recurrent pericarditis: Enlightening the pathogenesis for a more rational treatment. Trends Cardiovasc Med 2021;31:265-274. doi: 10.1016/j.tcm.2020.04.006. [2]Tombetti E, Casarin F, Bizzi E, et al. Relapsing pericarditis: peripheral blood neutrophilia, lymphopenia and high neutrophil-to-lymphocyte ratio herald acute attacks, high-grade inflammation, multiserosal involvement, and predict multiple recurrences. Int J Rheum Dis. 2022. doi: 10.1111/1756-185X.14523. Online ahead of print. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.